Furnace



C. F. GUHLMAN.

FURNACE.

APPLICATION FILED JULY 24. 1919.

1,370,309. Patented Mar. 1,1921.

2 SHEETSSHEET I.

25 IRA/EN 705/ 72' 7 fi/mr/as ZGuh/maa. By 5%,MM4 99 7 C. F. GUHLMAN.

FURNACE.

APPLICATION FILED JULY 24. 1919.

Patented Mar. 1, 1921.

2 SHEETS-SHEET 2.

6 JT/I/EA/Tm/ 7 Ch 4 465 7. 1/5 #7240? f yui i i'reo STAT-ES pAr-eu'rorrlce.

CHARLES I. GUHLEAN, OF CLEVELAND, OHIO, ASSIGNOB 'IO THE GRASSELLI CHEMI- CAL COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

FURNACE.

Specification oIIetters Patent.

' Patented Mar. 1, 1921.

Application, filed July 24, 1919. Serial No. 812,990.

To all whom it may concern:

Be it known that I, CHARLES F. Gum.- MAN, a citizen of the United States, and a resident of Cleveland, county of Cuyahoga, and State of Ohio, have invented a new and useful Improvement in Furnaces, of which the followmg is a specification, the principle of the invention being herein explained and the best mode in which I'have contemplated like.

One object of the present invention is the provision of an improved stirring means for agitating and discharging the material on the hearth of such a furnace, particular attention being given to the construction of such stirring means in order to permit of the quick and convenient removal of broken or worn parts. A further object of the invention is the provision of an improved feeding mechanism to operate in conjunction with the hearth and stirring mechanism of such a furnace. Other objects of the invention will appear from the followin description. To the accomplishment o the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims.

The annexed drawings and the following description set forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawings Figure 1 is a vertical central section through a furnace embodying my improve ments; Fig. 2 is a plan view of the distributing spouts for the material; Fig. 3 is a plan view of the stirring mechanism; Fig. 4 1s a transverse section on the line 44, Fig.

3; Fig. 5 is a similar section taken adjacent perature.

to and looking toward the central hub; Fig. 6 1s a plan view of my improved rabble; F1g. 7 is a longitudinal section through the end of one of the stirring arms; and Fig. 8 1s a view in elevation of a detail of construction.

In Fig. 1 the general construction of the furnace is shown. In this furnace there is a furnace chamber 1, the bottom of which is covered by a hearth 2 of substantially circular form, provided with a recess or pot 3 about its center, while through the center of this recess extends a shaft 4, upon the upper end of which is mounted a hub 5 for receivin the agitating arms which carry the rabbles or mixing and discharging the material on the hearth.

Mounted on top of the hub 5 is a materialdelivery mechanism adapted to be removably, but snugly fitted over the hub and to rotate therewith. This mechanism consists of a vertical hollow portion 6 leadingto a plurality of radially directed horizontal feeding spouts 7, of which there may be one or more, and into the upper end of the hollow portion 6 extends a feed pipe 8. This feed pipe is'set into, and extends through a thimble 9, which extends through the top 10 of the furnace, and at its upper end is connected to an open chamber 11, into which extendsa trough or feed conduit 12. This feed conduit 12 is inclined at an angle and its upper end is placed adjacent to the side wall 13 ofa material reservoir 14 in the form of a box, which is set into a larger chamber 15 connected by a passage 16, with the top of the combustion chamber in the furnace, in order to permit the products of combustion to pass around the reservoir 14 and maintain the same at the desired tem- It is desirable to maintain the reservoir at a considerable temperature, in some cases at a temperature of from 375 to 400 degress F., as in the'manufacture of muriatic acid by present processes it is cus- 'tomary to feed molten niter cake to the hearth of the furnace, and this niter cake which is contained in the reservoir 14 must spout7 to the hearth, is secured by means of a tiltable bucket 17 connected to a reciprocable rod 18, and normally held against the side wall 13 of the reservoir. As this bucket is dipped into the material in the res ervoir and then lifted it is prevented from tilting by the guiding action of the wall 13 of the reservoir until the bucket has reached the top of this wall when it tilts 'into alinement with the trough or conduit 12 and discharges thereinto. After discharge, it is returned to the reservoir 14 and is tilted into the position shown by. means of the guiding wall 13. Salt or other desired material may be separatel fed to the hearth through a conduit 60 y means of a screw conveyer dischar ing 'onto an inclined. trough 61 which elivers into the pot.

In order. to secure a constant production of gas and revent peak loads of sudden evolution of arge amounts of gas that have been produced in furnaces of other types, it is essential that a constant feeding of the material be maintained to the hearth of the furnace, and also that the material on the hearth be systematically agitated and regularly fed or discharged from the hearth through a normally closed chute 18 in the side of the furnace. One objection which has been found in furnaces which arev at present in general use for the manufacture of muriatic acid is that a very heavy strain is sometimes put upon the arms 20, which are attached to the central rotating hub 5, causing a breakage of those arms. It has been necessary whenone of these arms 20 broke to stop the furnace and then allow it'to cool down sufliciently for workmen to enter the furnace chamber and replace it with a new one. The same trouble occurred when the rabbles or projections carried by the arms were worn to such an extent that they did not approach the surface of the hearth, and as the rabbles wore out in a few days, and as the arms broke at frequent in tervals, it will be evident that such a fur-- nace would have to be shut down for repairs a very large part of the time, and in many cases this has amounted to one-half of the total working time of the furnace. I have designed improved arms which may be conveniently removed from the central hub from the outside, and rabbles which can also be removed and replaced by workmen from the outside, so that while the furnace must be stopped for these repairs it is not necessary that it be allowed to get cold, and consequently five days or more are saved at each breakage of the rabbles.

In Figs. 1, 3, 4 and 5, I have shown the construction of my improved arms, each of which isformed hollow and provided with a flange 21 adjacent its inner end, which is adapted to abut snugly against the outer face of the hub 5 about the opening therein. Between the flange 21 and the face of the hub are interposed gaskets 22 of metal and asbestos, which prevent any rusting together of the flange and-the hub, as has often happened in the past where the metal surfaces of these two parts are in contact, due to the corrosive action of the acid gas arisin from the furnace. Each arm is also provided with an extending lug 23 on the fiange2l, which is adapted to engage against 9. lug 24, formed on the base of the hub to prevent turning of the arm in the hub, by reason of the turning moment exerted thereon by the resistance of the material to the passage of the rabbles therethrough.

The hub 5 is provided with two pairs of diametrically opposed openings for receiving the arms, and as the arms are formed hollow there is a clear passage from the outer end of each arm to the outer end of that arm which is diametrically opposite to it. Through these openings is inserted a tie rod 29, on either end of which is mounted a nut 25 adapted to engage against the outer end of the arm 20. The nut'is screwed on to, and is spaced from the arm 29 by means of a combination metal and asbestos washer or gasket 28 in order to prevent any rusting together of the nut 25 and tie rod 29, and also to prevent any rusting together where nut 25 abuts the arm 20. The tie rods 29 are provided with central portions which are slightly ofi'set so that they will pass one another in the center of the The ends of the arms 20 are securely attached together by means of jointed tie rods 30, each of which is fastened to a collar 31 mounted on the end of each of the arms 20..

The joint in the tie rods 30 is secured by means of a turnbuckle 32, and rusting of this turnbuckle is avoided by the use of metal and asbestos washers 33 at both ends of the buckle. These circumferentially extending tie rods fasten the arms 20 and the hub 5 together in a rigid structure and distribute any sudden strain on any of the arms through the entire construction, and in this way tends to prevent thebreakage of the arms. When it becomes necessary to remove one of the arms, the tie rods con-- formed on one side of each of the arms 20.

These arms 20 are also formed on either under side with a curved shoulder 37 the curvature of which is that of an arc swung about the point 38 as an axis, and-a similarly curved extension or lug 39 is formed on the inner side of each of the rabbles 34. .Thus the rabbles 34 may be swung into position on the arms 20, or swung out of osition for removal without any contact etween the lug 39 and the shoulder 37 on the arm. The rabbles are prevented from turning or twisting when once engaged on the arms 20 by means of the length of the bearing surface between the hook-shaped upper ends of the rabbles and the shoulder 36 on the arms, and also by means of lugs 40 which are formed on the arms on either side of the normally desired position of the rabbles.

It is desirable. to have an extremely hard and wear resisting surface on the ra-bbles, which of course are extended to engage in and agitate the material on the hearth of the furnace, but it has been impossible to give the rabbles the hardness which has been desired as this lessened the toughness and strength of the rabble arms, which were then readily broken when resisted by large lumps of material on a hearth. I have avoided this diiiiculty by making the rabble shank 34 proper of extremely tough material and then mounting removable shoes 42 on the lower arms of the rabbles. These shoes may then be given any desired hardness and may be formed of very hard and even brittle material which will resist wear much better and be less liable to breakage than the material used in the past. These shoes 42 are of roughly triangular outline, the forward end 43 of each extending to a rather blunt point and being then broadened and curved on the circumferentially outer side 14 of the shoe. The shoes are of considerable thickness and are provided with a pocket or recess 45 in their upper sides, in which are received the lower ends of the rabbles 34, which are then desirably cemented firmly thereto so that there will be no play between the shoe and the rabble. My improved rabbles are designed to last very much longer than rabbles of the old style, particularly if made of duriron or of fused bauxite, while the danger of breaking rabble irons and shanks is also eliminated to a very great extent by the use of an asbestos cushion between the rabble shanks and the shoes. In this way a slight amount of play may be allowed between the shank and the shoe, with the asbestos packing acting as a shock absorbing cushion.

It will be obvious that the bottom surface of the rabble shoes must conform to some extent to the hearth, that is, where the hearth Y is depressed to form the recess 3, the rabble shoes must be formed to lie flat on this surface. Otherwise, the several rabbles disposed along the arms are similar in construction and function.

The chute 18 drops vertically from the hearth and in this way affords a discharge passage for the material which is not closed by the sticking of the material to the sides of the passage as has been found to be the case where the material is discharged in an inclined chute in which the material is obliged to slide along one surface of the chute. The bottom of the chute 80 is normally closed by a hinged cover 50 pivoted about a horizontal axis and maintained in a closed position by means of a counterweight 51 and latches 52. The latches, two in number, are also pivoted upon horizontal axes and are maintained in their locking position by means of counterweights 53.

The material will build up upon the door or cover 50 until a sufficient weight is reached to overcome the counterweights 51 and 53,- when the cover will open, dumping the entire Weight of material into a buggy or car 54 disposed below the furnace upon a suitable track. The counterweight 51 will then return the door to its closed position and the door will reach this position by swinging the latches 52 on their axes, each latch being provided with a rounded surface 55, against which the cover contacts and causes operation of the latch as described.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention 1. In mechanism of the character described, the combination of a central rotatably mounted hub provided. with a plurality of radially directed equidistant openings therein, a series of arms removably set into such openings, means adapted to secure said arms therein, and circumferentially extending means connecting said arms.

2. In mechanism of the character described, the combination of a central ro tatably; mounted hub provided with a plurality of radially directed equidistant openings therein, a series of hollow arms re movably set-into such openings, tie rods extending through said hollow arms, said rods being adapted to removably secure said arms to said hub, and a series of circumferentially extending rods removably and adjustably securing the outer ends of said arms together.

3. In mechanism of the character described, the combination of a central rotatable hub provided with two pairs of diametrically opposed radially directed and connected openings therethrough, a hollow arm removably mountedin each of said openings, common tie rods extending through each pair of said opposed arms,

said tie rods being removably secured to the outer ends of said arms and adapted to maintain the same in said hub, and circumferentially extending ad'ustable rods attached to the outer ends 0 said arms.

4. In mechanism of the character described, the combination of a central rotatable hub provided with two pairs of diametricall opposed radially directed and connected openings therethrough, a hollow arm removably mounted in each of said openings, common tie rods extending through each pair of said opposed arms, said tie rods being removably secured to the outer ends of said arms and adapted to maintain the same in said hub, collars mounted on the outer end of said arms and circumferentially extending rods removably attached to said collars, said last-named rods being adapted to secure said arms to gether to form a braced and rigid structure.

5. In mechanism of the character described, the combination. of a central rotatable hub provided with two pairs of diametrically opposed radially directed. and connected openings therethrough, a hollow arm removably mounted in each of said openings, common tie rods extending through each pair of said opposed arms, said tie rods being removably secured to the outer end of said arms and ada ted to maintain the same in said hub, col ars mounted on the outer end of said arms, and circumferentially extendin adjustable rods removably attached to sai collars, said last-named rods being jointed and adapted to secure said arms together to form a braced and rigid structure.

6. In a furnace mechanism, the combination of an arm mounted to move over a furnace hearth, and a rabble provided with a hook-shaped upper end adapted to en age over one side of said arm and a curve extension on the lower end adapted to enga under the arm, said rabble being thereby adapted to be maintained in engagement. with said arm during movement of the latter in one direction,

7. In a furnace mechanism, the combination of an arm mounted to move over a furnace hearth, a' rabble provided with a hookshaped upper end adapted to engage over one side of said arm and a curved extension on the lower end adapted to engage with a shoulder on said arm, and means mounted on said arm and adapted to prevent lateral displacement of said rabble.

8. In a furnace mechanism, the combination of an arm mounted to move over a furnace hearth, a rabble provided with a hook shaped upper end adapted to engage over one side of said arm, and spaced lugs mounted on said arm on either side of thenormal position of said rabble, said lugs being adapted to maintain said rabble in such normal position.

9. A rabble comprising a shoe of hard wear-resistant material provided with a recess therein, and a shank disposed snugly within such recess.

10. A rabble comprising a shoe of hard Wear-resistant material provided with a re cess therein, and a shank of tough material disposed within such recess and cemented thereto.

11. A rabble comprising a shoe of fused bauxite provided with a recess therein, and a metal shank disposed within such recess and cemented thereto.

12. A rabble comprising a shoe of duriron 80 provided with a recess therein, and a metal shank disposed within such recess and cemented thereto.

Signed by me this 16th day of July, 1919.

v CHARLES F.- GUHLMAN. 

